Radio-controlled aircraft
A radio-controlled aircraft is a small flying machine that is radio controlled by an operator on the ground using a hand-held radio transmitter. The transmitter continuously communicates with a receiver within the craft that sends signals to servomechanisms which move the control surfaces based on the position of joysticks on the transmitter. The control surfaces, in turn, directly affect the orientation of the plane.
Flying RC aircraft as a hobby grew substantially from the 2000s with improvements in the cost, weight, performance, and capabilities of motors, batteries and electronics. Scientific, government, and military organizations are also using RC aircraft for experiments, gathering weather readings, aerodynamic modeling, and testing. A wide variety of models, parts, and styles is available for the DIY market.
Nowadays, distinct from recreational civilian aeromodelling activities, unmanned aerial vehicle or spy planes add a video, GPS or autonomous feature, enabling instrumental RLOS or BLOS capabilities, which are used for public service or commercial purposes, and if in the service of a military or paramilitary, may be armed.
History
The earliest examples of electronically guided model aircraft were hydrogen-filled model airships of the late 19th century. They were flown as a music hall act around theater auditoriums using a basic form of spark-emitted radio signal.The British drone weapons in 1917 and 1918 evolved and their development continued through the work of the Royal Aircraft Establishment resulting in the fleet of over 400 Queen Bee UAV Target Aircraft in the 1930s.
During World War II, the U.S. Army and Navy used radio controlled planes called Radioplanes as artillery target drones.
The National Model Aviation Museum located in Muncie, Indiana hosts the world's largest collection of RC aviation history. They display models from every era of RC donated by the RC community around the world. They also have kit plans that RC pilots can purchase to build models from every era. The museum is located on the same grounds that the Academy of Model Aeronautics main office is located.
Types
There are many types of radio-controlled aircraft. For beginning hobbyists, there are park flyers and trainers. For more experienced pilots there are glow plug engine, electric powered and sailplane aircraft. For expert flyers, jets, pylon racers, VTOL planes, helicopters, autogyros, 3D aircraft, and other high-end competition aircraft provide adequate challenge. Some models are made to look and operate like a bird instead. Replicating historic and little known types and makes of full-size aircraft as "flying scale" models, which are also possible with control line and free flight types of model aircraft, actually reach their maximum realism and behavior when built for radio-control flying.Radio-control scale aircraft modeling
Perhaps the most realistic form of aeromodeling, in its main purpose to replicate full-scale aircraft designs from aviation history, for testing of future aviation designs, or even to realize never-built "proposed" aircraft, is that of radio-control scale aeromodeling, as the most practical way to re-create "vintage" full-scale aircraft designs for flight once more, from long ago. RC Scale model aircraft can be of any type of steerable airship lighter-than-air aviation craft, or more normally, of the heavier-than-air fixed wing glider/sailplane, fixed-wing single or multi-engine aircraft, or rotary-wing aircraft such as autogyros or helicopters.Full-scale aircraft designs from every era of aviation, from the "Pioneer Era" and World War I's start, through to the 21st century, have been modeled as radio-control scale model aircraft. Builders of RC Scale aircraft can enjoy the challenge of creating a controllable, miniature aircraft that merely "looks" like the full scale original in the air with no "fine details", such as a detailed cockpit, or seriously replicate many operable features of a selected full scale aircraft design, even down to having operable cable-connected flight control surfaces, illuminated navigation lighting on the aircraft's exterior, realistically retracting landing gear, etc. if the full-sized aircraft possessed such features as part of its design.
Various scale sizes of RC scale aircraft have been built in the decades since modern digital-proportional, miniaturized RC gear came on the market in the 1960s, and everything from indoor-flyable electric powered RC Scale models, to "giant scale" RC Scale models, in scale size ranges that usually run from 20% to 25%, and upwards to 30 to 50% size of some smaller full scale aircraft designs, that can replicate some of the actual flight characteristics of the full scale aircraft they are based on, have been enjoyed, and continue to be built and flown, in sanctioned competition and for personal pleasure, as part of the RC scale aeromodelling hobby.
Sailplanes and gliders
are planes that do not typically have any type of propulsion. They can be towed into the air by use of another aircraft with an engine, and once at a high altitude, the glider can release from the tow rope. Unpowered glider flight must be sustained through exploitation of the natural lift produced from thermals or wind hitting a slope. Dynamic soaring is another popular way of providing energy to gliders that is becoming more and more common. However, even conventional slope soaring gliders are capable of achieving speeds comparable with similar sized powered craft.Gliders are typically partial to slow flying and have high aspect ratio, as well as very low wing loading. Two and three-channel gliders which use only rudder control for steering and dihedral or polyhedral wing shape to automatically counteract rolling are popular as training craft, due to their ability to fly very slowly and high tolerance to error.
Powered gliders have recently seen an increase in popularity. By combining the efficient wing size and wide speed envelope of a glider airframe with an electric motor, it is possible to achieve long flight times and high carrying capacity, as well as glide in any suitable location regardless of thermals or lift. A common method of maximising flight duration is to quickly fly a powered glider upwards to a chosen altitude and descending in an unpowered glide. Folding propellers which reduce drag are standard. Powered gliders built with stability in mind and capable of aerobatics, high speed flight and sustained vertical flight are classified as 'Hot-liners'. 'Warm-liners' are powered craft with similar abilities but less extreme thrust capability.
Jets
commonly use a micro turbine or ducted fan to power them. Most airframes are constructed from fiber glass and carbon fiber. For electric powered flight which are usually powered by electric ducted fans, may be made of styrofoam. Inside the aircraft, wooden spars reinforce the body to make a rigid airframe. They also have kevlar fuel tanks for the Jet A fuel that they run on. Most micro turbines start with propane, burn for a few seconds before introducing the jet fuel by solenoid. These aircraft can often reach speeds in excess of 320 km/h. The high speed requires greater skill to operate.In the U.S.A. the FAA restricts flying of such aircraft to approved AMA Academy of Model Aeronautics sites, where only certified turbine pilots may fly. Also, the AMA requires model aviation enthusiasts who wish to operate miniature gas turbine powered RC model aircraft, to be certified in the operation of the type of gas turbine engine, and all aspects of safety in operating such a turbine-powered model aircraft, that they need to know in flying their model. Some military bases allow such high tech aircraft to fly within limited airspace such as Kaneohe Marine base in Hawaii, and Whidbey Island NAS in Washington State.
An average turbine aircraft will cost between US$150–US$10,000 with more than US$20,000 all-up becoming more common. Many manufactures sell airframes such as Yellow Aircraft and Skymaster. Turbines are produced from The Netherlands to Mexico. The average microturbine will cost between US$2500 and US$5000 depending on engine output.
Smaller turbines put out about 12 lbf of thrust, while larger microturbines can put out as much as 45 lbf of thrust. Radio-control jets require an onboard FADEC controller; this controls the turbine, as on a full-size aircraft. RC jets also require electrical power. Most have a lithium polymer battery pack at 8–12 volts that controls the FADEC. There is also a LiPo for the onboard servos that control ailerons, elevator, rudder, flaps and landing gear.
Of much less complexity are the types of RC jet aircraft that actually use an electric motor-driven ducted fan instead to power the aircraft. So called "EDF" models can be of much smaller size, and only need the same electronic speed controller and rechargeable battery technology as propeller-driven RC electric powered aircraft use.
Radio-controlled jet aircraft are produced in the colors of various airlines. Among the most popular airline liveries used by modelers are those of American, Singapore, Pan Am, Etihad and Delta Air Lines.
Sports planes
Sports planes are planes capable of performing aerobatic maneuvers involving aircraft attitudes that are not used in normal flight. Typical aerobatic maneuvers include inside loop, outside loop, Immelmann turn, inverted flight, stall turn, slow roll and Cuban 8.3D planes
3D flight is a type of flying in which model aircraft have a thrust-to-weight ratio of more than 1:1, large control surfaces with extreme throws, low weight compared to other models of same size and relatively low wing loadings. Simply put, 3D flight is the art of flying a plane below its stall speed.These elements allow for spectacular aerobatics such as hovering, 'harriers', torque rolling, blenders, rolling circles, flat spins, and more; maneuvers that are performed below the stall speed of the model. The type of flying could be referred to as 'on the prop' as opposed to 'on the wing', which would describe more conventional flight patterns that make more use of the lifting surfaces of the plane.
3D has created a huge market for electric indoor 'profile' types similar to the Ikarus 'Shockflyers' designed to be able to fly inside a gym or outside in little wind. These generally make use of small brushless motors and lithium polymer batteries. There are also many larger 3D designs designed for two and four stroke glow engines, two stroke gas engines and large electric power systems.